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Reclaimed water for Olympic venues
By Guan Xiaomeng (chinadaily.com.cn)
Updated: 2007-07-19 14:10
The water looks fresh and clean under the clear blue sky on a Wednesday afternoon, but it's produced from sewage water. Coming from the city sewage and reclaimed at the Qinghe Water Reclamation Plant (Qinghe WRP), this reclaimed water helps cut down on water consumption of Beijing's lakes and rivers.
Reclaimed water is seen in a water pool in Qinghe Water Reclamation Plant. [chinadaily.com.cn] |
The media was invited by the Organizing Committee for the Beijing Olympic Games (BOCOG) to visit the sewage treatment plant and see first-hand how water reclamation works at the plant in the north of the city.
Holding a glass of reclaimed wastewater, Zhang Jianxin, senior engineer Beijing Drainage Group said the reclaimed water they produced from city sewage water could be used for industry, irrigation and urban purposes except for human consumption.
Zhang Jianxin, senior engineer Beijing Drainage Group holds a glass of reclaimed water and speaks to the visiting media. [chinadaily.com.cn] |
As a city running short of water but welcoming the nation's first Olympics in one year's time, Beijing is going all out to support the Olympic water supply and maintain its brisk economic growth.
With four reclamation plants, two reused water pumping stations and 4,000 km of distribution pipeline working for the city, 2.5 million cubic meters of water is processed per day, accounting for the 90 percent of the city's total wastewater, the goal set by the city government for the 2008 Olympic Games.
"Of the 90 percent of wastewater processed, 46 percent is recycled. We finish building another reclamation plant called Bei Xiaohe by the end of this year before the Games. This will help us to reach the 50 percent ratio, and that is our target," explained Yang Xiangping, general manager of the Beijing Drainage Group.
Qinghe WRP, together with Bei Xiaohe plant to be completed this year, will pump high quality reclaimed water for the Olympic central area, which is located on the north end of city. Bei Xiaohe, according to the press release, will produce even higher quality water than that by Qinghe.
According to Wang Hongchen, chief engineer of the Group, Qinghe WRP uses a world-class ultra-filtration membrane technology to clean the water. First the water is separated from the sewage and this is called effluent water.
Water is oxidized with ozone in an activated carbon filtration tank. [chinadaily.com.cn] |
Then, this water, which is also called feedwater enters each cell or fibrous material from the bottom of the membrane cells and is drawn through several sheets of this material by suction from the filtration pump. Then the water from this membrane system flows to an activated carbon filtration tank and then oxidized with ozone to become relatively clean water.
Moreover, the Qinghe reclaimed water will run to the nearby Haidian and Chaoyang districts for urban uses such as road cleaning and watering roadside plants and flowers. In that way, about 30 million cubic meters of water will be saved annually.
To ensure a safe sewer network during the Olympics, the company has build a Geographic Information System (GIS) underground to monitor the sewer network. The staff displayed a robot that monitors and repairs the sewer pipes.
Now six Olympic venues are connected with the plant to use the reclaimed water it produces. The company said 77 km of pipes would be laid underground to transport reclaimed water to Olympic venues by the end of this year.
It smelt of sewage at the entrance of the reclaimed water processing line, where the sewage water was being processed. "We have about 240 tons of sludge per day after the sewage waster is cleaned," the chief engineer explained.
"But the sludge is not waste at all," Wang added, "We are building a sludge processing system introduced from Germany to turn it into fertilizer. We will provide 60 tons of fertilizer to Beijing's farmlands every day with the system."
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